Brake



March 23, 1937.

D. M. HUFFMAN ET Al.

Filed March 26, 1936 BRAKE 2 Sheets-Sheet l i DfM. HUFFMAN ET AL.2,074,651 I BRAKE March' 23, 1937.

Filed March 2e, 195e 2 sheets-sheet 2 3 W @www MHuff/nan i atente BRAKEDonald 1W. Huffman and William iF. YFriend.. Keyser, W. Va., assignorsoi one-third to .lohn lil. Massie, lr., Edinburg, Wa.

nppiication Marcin ze, i936, sei-iai No. 'frost s claims.

This invention relates to brakes designed pri-r marily for use on motorvehicles utilizing internal v combustion engines. y

It is an object of the invention to utilize vacuumand compression as ameans for retarding the movement of the vehicle on down grades, saidmeans being employed when desired, to supplement the usual frictionbrake.

Another object is to provide a brake of this type which will notover-heat and will not set up anyundesirable vibrations while it is inaction.

A further object is to provide a brake which is especially useful inconnection with trucks or other heavy vehicles used on mountain roads orwherever steep and dangerous grades are encountered.

With the foregoing and otherobjects in view which will appear as thedescription proceeds, the v invention consists of certain novel detailsof construction and combinations of parts hereinafter' more fullydescribed and pointed out in the claims, it being understood thatchanges may beI made in the construction and arrangement of partsWithout departing from the spirit of the invention as claimed.

In the accompanying drawings the preferred form of the invention hasbeen shown.

In said drawings Figure 1 is a side elevation showing an internalcombustion engine and the present improvements combined therewith.

Figure 2 is an enlarged section through the compression cylinder andshowing its relief valve.

Figure 3 is a section through the .connection wbetween the carbureterand the intake manifold,

the valve therein being shown in section.

Figure 4 is a view partly in section and partly in elevation showingthe-brake mechanism in 'normal position;

Figure 5 is a similar View showing the brake fully applied.

Figure 6 is an elevation of the yieldable, lost motion connectionbetween the brake pedal and the choke valve.

Referring to the figures by characters of reference A designates aninternal combustion engine with Vtlhe usual intake manifold B andexhaust 1 -manifold C. v Interposed between the carbureter D andth'eintake manifold B is a tubular valve casing or sleeve I in which asupplemental or auxiliary valve 2 is mounted to move about a centraltransverse axis 3. This valve is used in addition to the usuallcarbureter control valve. An arm t is located outside of casing l andmoves with valve 2.

into a compression cylinder l.

(Cl. 18S-99) An expansion chamber li is located adjacent to and incommunication with the exhaust manifold C and extending from thisexpansion chamber is an exhaust pipe 6 the back end of which opens Anoutlet is provided in the back end of this cylinder and extending acrossthe cylinder is a partition 9 having a valve seat ill. A valve il has astem l2 guided in `the back end of cylinder l and a spring i3 which ismounted on this stem and' within a socket lll in the end wall of thecylinder, thrusts against a. nut l5 or the like on stem i2 and serves tohold the valve normally closed against seat lll.

'I'he usual foot pedal of a vehicle brake has been indicated at i6 andhas an arm i'l movable therewith for pulling through a rod i8 upon anarm I9 extending from a transverse shaft 20. This pedal is yieldinglysupported in the usual manner. Arms 2| carried by this shaft have rods22 extending to the usual mechanical brakes, not shown.

A lever`23 is fulcrumed adjacent to cylinder l and one armthereof isadapted to swing against rstem i2 to unseat valve li, while the otherarm is connected ,by a rod 2t to arm I9.

Pivotally connected to the brake pedal lli at 25 is a thrust member 26having an intermediate offset portion 2l constituting aV guide ear whileanother guide ear 28' is formed by oisetting one end of the thrustmember. A rod 29 is slidable in these ears and. pivotally connected atone end to the arm t of the valve 2. A collar 30 is secured to ythis rodbetween the ears and receives thrust fromone end of a coiled springmounted on the rod, the other end of the spring bearing against ear 2l.Normally the collar 30 is thrust against ear 23 as shown in Figure 6,

When the engine is operating, fuel will be drawn through casing l intomanifold B while spent exhaust gases will be discharged into chamber 5and thence into pipe 6 and cylinder l. Normally the lever 23 holds valvelli open so that the gasescan escape through the outlet To applythebrake, the foot is removed from the accelerator as usual and pedal it isthrust forward a short distance so as to release valve l l for movementtoward its seat. sucked into the cylinders of the engine, thus will beforced out Ainto the exhaust manifold C and thence to chamber 5, pipe 6and cylinder l Where it will be compressed quickly by the rapidlyreciprocating engine pistons, the degree of compression depending uponthe position of the valve il relative toits seat. Further forward move-Gas and/or air ment of pedal I6 will result in complete closingv of thevalve I l and this will be followed by offset 21 pressing against andcompressingvspring 3l,

thereby closing' valve 2. Consequently subsequent reciprocations of theengine pistons will create vacuums between them and the Closed valve 2as well as compression of the air and/or gas already compressed betweenthe pistons and the valve Il.

It has been found in practice that this double retarding action set upby compression and Vacuum or suction, as explained, will enable a vejhicle to be kept under complete control when descending any grade.Therefore the invention is especially useful in those localities wheresteep grades frequently are encountered.

What is claimed is: 1. I'he combination with an internal combustionAengine having an exhaust manifold and an intake manifold, of mechanicalbrake mechanism including an operating element, and a vcom pressionbrake mechanism comprising a compression cylinder communicating with theexhaust pipe and having an outlet, a valve in the cylinder, meansconnected to the operating eleoutlet of the cylinder.

2. The combination with an internal combustion engine including acarbureter, of mechanical e brake mechanism including an operatingelement, and compression brake mechanism including a compressioncylinder in communication with the exhaust manifold of the engine, avalve in the cylinder, a normally open valve between the intake manifoldand the carbureter and separate from the carbureter for controlling theflow of air and/or gas to the engine, means operated/by the said elementfor holding the cylinder valve open and for releasing said valve, meansfor closing said cylinder valve when released to shut off the escape ofgases from the cylinder, and means operated byy said operating elementfor effecting a delayed actuation of the air control valve.

3. The combination with an internal combustion engine having acarbureter and intake and exhaust manifolds, of an auxiliary valve forcontrolling the ilow of air and/or gas to the intake manifold from thecarbureter, a compression cylinder communicating with the exhaustmanifold and having an outlet, a normally 'open valve in the cylinderfor controlling the escape of air or gas through the outlet, a normallyrestrained spring for closing the cylinder valve, brake mechanism, afoot pedal movable in one direction to actuate said mechanism, andseparate means operated by said pedal for releasing'the spring f toclose the cylindervalve and thereafter closing the auxiliary valve.

DONALD M. HUFFMAN. WILLIAM F. FRIEND.

